Stable vertical element



Nov. 14, 1950 A. P. DAVIS 2,530,154

STABLE VERTICAL ELEMENT Filed sepia. 28, i945 s sneeTs-shgerl llllrll/lr;

[lill/[lll Q INVENTOR.'

2 ARTHUR P, Dfw/6,

Nov. I4, 1950 A. P. DAVIS 2,530,154

' STABLE VERTICAL ELEMENT Filed Sept. 28, 1945 3 Sheets-Sheet 2 'f ATToRNEYs.

Nov. 14, 1950 A, P. DAvls 2,530,154

STABLE VERTICAL ELEMENT Filed Sept. 28, 1945 3 Sheets-Sheet 3 Zz za INVENTOR: rhar DJV/5,

C f rom Com/bars Patented Nov. 14, 1950 STABLE VERTICAL ELEMENT Arthur P. Davis, New York, N. Y., assignor to Arma Corporation, Brooklyn, N. Y., a corporation of New York Application September 28, 1945, Serial No. 619,224

(Cl. 'i4- 5.44)

20 Claims.

This invention relates to stable vertical elements and has particular reference to improvements in mercury ballistic erecting systems for such elements.

In naval shipboard instruments for indicating the vertical by gyroscopic action, controlled mercury flow has been found to be the most practical means of causing the gyroscope to precess back to the vertical When it departs therefrom. In the operation of such control systems, departure of the gyroscope from the vertical causes mercury to ow from one tank to another on the gyroscope case through a restricted pipe, thus producing a displaced fore-couple upon the gyroscope, causing it to precess back to the vertical. Mercury has been chosen for this purpose because of its weight per unit of volume and its low viscosity, causing quick response to gravity. I-Iowever, these same properties of the mercury also cause it to be equally sensitive to disturbing forces, such as acceleration an`d,`for this reason, it has been found expedient to block the mercury flow when acceleration is present. This expedient, which leaves the gyroscope Withoutcontrol when under acceleration during a small interval of time, Was practical when gun-fire was limited to straight line sailing at uniform speed or on slow curves, but changed conditions of rapid maneuvering with frequent changes in course and speed in naval Warfare have made continuous firing imperative under all conditions of travel. It has therefore become essential that control of the gyroscope be continuous and, as a consequence, the effect of acceleration on the system must be neutralized in so far as is practicably possible.

In certain stable elements using a mercury control system having two tanks mounted diametrically opposite each other on the case of the gyroscope wheel and interconnected by means of a pipe having a certain constriction, the gyroscope case together with the attached tank system is continuously rotated about a substantially vertical axis at a speed determined by the constants of the mercury system, so that resonance effects appear. The flow of the mercury lags, roughly, a quarter turn behind any tilt of the gyroscope from the vertical, and in this way a torque is produced on the gyroscope, when tilted, which is in the proper plane to precess it back to the vertical. The problem of shift of mercury caused by acceleration, however, hasnot been solved', but has Vbeen merely avoided by plugging the mercury flow pipe whenever acceleration was present, the gyroscope then being derelict and free to drift until-'the'acceleration disappeared, so that during 55 indicates the true vertical.

the slightest degree.

such periods the gun-lire control operations were deprived of a reliable reference upon which to base accurate calculations.

In accordance with the present invention, a mercury ballistic erecting system for a gyroscope stable element is provided-,which keeps the gyroscope continuously under con-trol of the mercury at all times, including periods of acceleration, by automatically mak-ing allowances for the same in a novel and effective manner. Inasmuch as the mercury must be free to respond to the slightest tilt of the system in order to correct any real deviation of the gyroscope, it necessarily is free to respond to acceleration forces also. Ordinarily, acceleration effects cause the mercury to flow and produce a head of mercury one tank over that iny the other, which unbalances the system with the result that a correction couple is imposed on the gyroscope for a departure from vertical Which does not actually exist.

In order to prevent this false response and at the same time to allow correction for any tilt which does exist, the preferred embodiment of the invention is arranged to permit the head of mercury to build up in one tank in proportion to the acceleration, Meanwhile, the consequent shift of the center of gravity is prevented by introducing into the high level and consequently heavy tank a light mercury-displacing body or float. In this way, the required acceleration head or gradient is built up Without permitting ow of mercury between tanks,A although the equivalent free flow of mercury `between them for correcting error in the gyroscope is not interfered with to The depth of insertion of the float into the mercury is predetermined in accordance with the factors which cause the disturbing acceleration, namely, ship speed and change of course, this measurement being made in a computer of any suitable type. Finally,cog nizance is taken of practical limitations in such measurements at sea and a novel mechanism provided to prevent over-correction from this cause.

It will be seen that the new mercury ballistic erecting system for a gyroscope stable element provides a very simple but effective arrangement for correcting the frequent acceleration effects that occur because of the evasive maneuvers of modern naval combat vessels and without disabling and thus depriving the gun-fire control system of a stable element at critical times, so that it may be fairly said that the inventionl permits the mercury system to operate about the virtual or apparent vertical while the gyroscope For a more complete understanding of the invention, reference may be had to the accompanying drawings, in which:

Figure l is an elementary diagram of a mercury tank and pipe assembly When level and not under acceleration;

Fig. 2 is a similar View of the assembly when tilted down at the left, but not under acceleration;

Fig. 3 is a similar view when not tilted but under acceleration and not corrected therefor;

Fig. 4 is a similar View when not tilted, but under acceleration and corrected by the system of this invention.

Fig. 5 illustrates in perspective a practical assembly of the sensitive unit of a stable element of well-known type with the system of this invention applied thereto;

Fig. 6 shows the mercury system of Fig. 5 in enlarged vertical section; and,

- Fig. 7 schematically illustrates an electrical arrangement for determining corrections in the system of this invention.

Referring to Fig. l, there is shown in diagrammatic form an assembly consisting of a tank IQ .joined to a similar tank II by a. bottom connect- -ing pipe I2. ltained in the two tanks and the connecting pipe Liquid, preferably mercury, is conand when, as in this gure, the system is level the height of the mercury is the same in both tanks. For this reason the center of gravity of the liquid is the midpoint I3 on the vertical line of symmetry III and the system is in equilibrium.

Assume that all conditions remain unchanged,

except that, owing to some disturbance, such as anced and a force-couple appears of the dimen- -sion Rt as indicated. If the tank system is rotated bodily about the vertical median line I4 as an axis, then when it is unbalanced as in Fig. 2, the force-couple Rt will not appear in the plane Voi" the tanks, but in some plane at an angle to them, due to phase displacement of the mercury iiow.

This phenomenon is well known and is commonly used to keep a gyroscope in the vertical, the constants of the system being chosen in such relation to the `speed of rotation that the couple Rt, used to erect the gyroscope upon departure from the vertical in the plane of the drawing, appears in a plane roughly perpendicular to that plane. By such means a gyroscope is made to keep the vertical within two minutes of angle, if stationary or if traveling in a straight line at uniform speed. However, when these conditions are not met, the gyroscope starts to align with the virtual vertical with loss of value as a stable element, thus introducing a serious error diiiicult to detect promptly. This condition is corrected in the system of the present invention, as will be explained in connection with Figs. 3 and 4.

Referring to Fig. 3, the same tank and tube assembly is shown in horizontal position but subjected to acceleration in the direction of the arrow ACC, thus causing mercury transfer in the opposite direction resulting in a gradient in the mercury level amounting, from one end to the other, to the head indicated at h. inasmuch as the quantity of the mercury in tank I I is greater than that in tank I0, a force-couple of the value Ra appears, as shown, although the assembly has 4 remained on even keel. Due to the resulting unbalance, a powerful but erroneous correction is imposed on the associated gyroscope for a departure from the Vertical which has actually not occurred. Thus the gyroscope will be over-corrected and a serious error created. The system, of course, is indifferent to origin of disturbances and cannot distinguish between gravity and acceleration forces.

Fig. 4 illustrates the novel arrangement whereby the mercury level gradient is permitted to satisfy the acceleration, while any unbalance of the system because of the acceleration is prevented. This is accomplished by introducing into the mercury in the overloaded tank II a light liquid-displacing member I5 of any desired shape, to such a depth that the total amount of mercury in tank I I is made equal to the total amount in the other tank I0. This displacement immersion depth is determined by mathematical calculation from known factors, such as speed of ship, rate of change of course and displacement rate of the introduced iioat. Should the acceleration be in the opposite direction, a similar float I6 is introduced into the other tank I Il. The means for effecting automatic control of the position of the floats will be made clear later.

Referring to Fig. 5, illustrating a preferred embodiment of the invention as applied to a wellknown stable element gyroscope assembly, the encased gyroscope I'I is mounted in the gimbal I8 which in turn is mounted for slow rotation in the fork I9 on the follow-up or phantom element 20 and driven by the motor 52. Carried on the gyroscope I1 is the connected mercury tank assembly 2l similar to that shown in Fig. i and shown in enlarged section in Fig. 6, by means of which the gyroscope I7 is kept substantially vertical, as above described. Mounted on the mercury tanks II! and Il are respective solenoids 23 and 22 whose permanent magnet armatures 23 and 22 are connected to the corresponding mercury displacement floats I5 and I6 for operating the same in the manner previously described in connection with Figs. 3 and 4. The mercury is indicated as completely filling the connecting pipe I2 and partially filling the tanks I0 and Il.

At the center of pipe I2 is shown in diagrammatic form the flow control valve 25 operated by solenoid 24. The whole device is shown on even keel so that the level of the mercury is the same height in both tanks. When this is the case, the mercury has no eifect on the gyroscope, since such a condition shows that the gyroscope has the desired orientation. The constriction in the pipe I2 is provided by the conical valve 25 cooperating with the conical seat 26. Valve 25 is held by spring 21 in a predetermined position against the adjusting screw 28 for normal operation in correcting the gyroscope when not affected by acceleration. When solenoid 24 is energized in response to acceleration, it pulls the armature 29 and connected valve 25 away from the screw 28, which action, due to the conical shape of the valve 25 and its seat 2E, progressively reduces the constriction in the pipe I2, thus permitting freer ilow of the mercury. This action reduces the speed of erection of the gyroscope, when the same is too high, due for instance, to error in calculated applied corrective values.

Referring to Fig. '7 which illustrates the electrical mercury system control circuit and means to apply corrective forces to the gyroscope, the mercury displacing floats I5 and I6 are shown S diagrammaticauy 'with their permanent .magnet armatures 22 and 2t-l arranged NS, SN within lthe'irfoperatilngfcoils22 and 23. The armature 29 f lthefidW-rate-controlling valve 275 is not magntizeil like-armatures -22 and 23', but is of soft liron,sb that it is .pulled vinto the vsolenoid 421| as a fuiicti'oii vof Vthe 4current 'strength-in coil 24, regardless ofthe direction of the current. -I-Iowrever, coils 1242 and 123, although connected iin series with .'c'oil -2`4 by wires "30, have-opposite polarity `armatures22 and/23', so that one 'float goes ldovvn when the other goes up. Such an arrangement Lis a preferred means of causing the appropriate fiioat to operateaccording to direction of the lac- :c'eleration io'r'c'e. YThe depth to which a float should ybe immersed for any given acceleration lis fa matter of -calculation and is readily 'con- -`trolled by apparatus -noW `t`o be described.

TWO `forms of acceleration "are in evidence on fa ship, firstly, simple acceleration in the foreand-aft plane of the ship dueto changeslin speed, and, secondly, Iathvvartship acceleration due to rapid turns or excessivero'lling if the stable .element is not mounted low in 'theship To calculate these accelerations the means illustrated in Fig. '7 are employed 'and comprise direct current generators v3| and 32 for producing voltages .proportional to, rstly, the rate of change of vspeed of the ship, and secondly, the centrifugal force due to rchange of course. Other small accelerations are neglected as immaterial, since the main accelerations cannot be accurately determined, due to `inaccuracy in estimating ships speed, for instance, among the other factors.

The eld of direct current generator 3| is energized'by'battery 33 and itsarmature is vdriven Aby thespeed indication shaft 34 of the tachom- Veter 35 which is driven-by the propeller shaft 36 jfof'the ship, as shown. In this way, the voltage output of generator .3| across the leads 3l, isproportional to'therate of change of speed of the ship, i.`e., fore-and-#aft acceleration. This voltage s applied to the diametrically opposite points A3B and 39 onthe circular'voltage divider 49. The winding of .-the voltage divider 49 is secured to the supporting frame and is electrically insulated therefrom.

The acceleration force due to changing course 'is -represented by the voltage output ofthe second direct current generator 32, whose Winding is Yenergized by the voltage value S proportional toships speed, by means of the wires 4| Afrom direct current generator 42 driven from propeller shaft-36 as shown. The armature of genrator 32 is driven by-a compass repeater 43, in accordance `with course, C, as shown. The output voltage of generator 32 of value S is impressed by leads 44 connected to diametrically opposite points 45 and 46 on the winding -of the voltage divider rfill, these points being at right angles to the points 38, 39, since the two driven through-gearing 50, fork I9, and shaft 5| "from the-gimbairotationmotor .152, Aasshwnin dgyIOSCOpe.

- eration.

6 Fig. 5. suders 41 and 4a rotate with `hub 49, and are connected by wires 51 and 58 to one'ter'- minal each of coils 22 and 23, respectively, whose other terminals are connected together `by wire 30 including the coil 24.

In operation of the stable element control of this invention, as the gyroscope Il and the mercury system 2| are rotated by motor 52 substan tially in the horizontal plane, the voltage divider 4'9 feeds voltages to the solenoids .22, 23 and .24 from the various calculators, and the factors are properly combined .by rotation of the member 49 with the gyroscope Il to oscillate the floats l5 and i6 for varying and periodically reversing the mercury head in the tanks and Il! due to any acceleration present. This artificial reversing of the mercury head in tanks i5 and counter to the acceleration mercury heads, is controlled by the voltage divided 4.9, which determines at what point in the rotation of lthe mercury system 2| the acceleration effects due to speed changes or those due to changes in course are adversely Yaffecting the mercury system :so

that the proper ydegree of correction must be applied, which is also determined.

As stated, effectsdue to changes in speed, oc-

curring substantially iore-and-aft, are Ypropor-l tional to the voltage developed in generator 3| and that voltage is impressed across :an equivalent 180'segn1ent 38, 39 of voltage 'divider 4i?, whereas the voltage proportional to acceleration due to changes in course, occurring substantially athwartshipsand developed in generator E32, `is impressed across an equivalent 180 segment "45, 455 of dividerfll and displaced fromthe speed change segments.

The voltage picked up by brushes l4l vandz48, almost invariably the'sum of speed change `iacceleration and course changeacceleration voltages in varying .proportions depending upon 4'the angular positions of the brushes, determines the depth of immersion of the oats I5 and IS :in the mercury in corresponding vtanks lifand |.,rfioat i5 being raised when float "i3 is'depressed, .and vice versa, as explained. Since the voltage out- .put of the divider 4E is proportional to thev effects of accelerationon the mercury at the instantaneous angle of rotation thereof by motor 52, the

Hence, the displacement mechanism yprovides a difference in head of mercury-in the tankswhich is substantially proportional to acceleration, and permits only suihcient unequalivolume of mercuryin the tanks'to cause precession of thegyroscope back to the vertical upondeparturetherefrom.

The net result or this arangement is that, when the ship ison even keel and an-accelerationoccurs,-the mercury, due to the acceleration, tends to build up in thetank as indicated in Figs. .3 and 4, but the oat i5 in thattankimnierses sufficiently to prevent transfer of mercury to that tank from the other one, thus itself creating a head in the tank proportional to'tiiena'cceh In other vwords, the oat is vimmersed in the mercury in the tank to a' depth justenough to build up the necessary head in the Yannular small space about it, -thuspreventing admission of mercury and preserving thebalanee of the system. Neverthelesspactual unbalance can'still cause ythe-mercury to flow for correction vofthe 7 Y'Finally', due to the solenoid 24, as the acceleration voltages increase, the valve 25 opens more and more, reducing the effect of the mercury on the gyroscope, in order not to over-correct the same as previouslyT explained.

Although a preferred embodiment of this invention has been described herein, many variations of the same may be employed to obtain the same effects. For instance, the whole mercury tank system 2l may be pivoted on the gyroscope case and oscillated with accelerations in such a way that it is caused to rotate about the virtual vertical, rather than about the true vertical, or equivalent flexible diaphragms in the tanks may be inated or advanced by compressed air, for instance, to control the mercury. Accordingly the invention should be measured by the following claims rather than by the specific embodiment disclosed herein.

I claim:

1. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system continuously about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support, mechanism for regulating the displacement of the liquid in said system in response to said acceleration while permitting substantially free flow of the liquid between said communicating receptacles, and operative connections between said means and said mechanism for compensating for the effect of acceleration on said system.

2. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support, counter-displacement mechanism including a member immersible in the liquid in each receptacle for increasing the head of liquid therein, and operative connections between said means and said mechanism for eiecting the immersion of said members in the corresponding receptacles.

3. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system continuously about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support, mechanism for regulating the displacement of the liquid in said system in response to said acceleration while permitting substantially free ow of the liquid between said communicating receptacles, operative connections between said means and said mechanism for compensating for the eiect of acceleration on said system, and means responsive to the angle of rotation of said system interposed iny the connections between said first means and said mechanism for controlling the degree of said displacement regulation in accordance with the degree of the acceleration eiect on said system at said angle.Y

4. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support, counterdisplacement mechanism including a member immersible in the liquid in each receptacle for increasing the head of liquid therein, operative connections between said means and said mechanism for eiecting the immersion of said members in the corresponding receptacles, and means responsive to the angle of rotation of said system interposed in the connections between said first means and said mechanism for controlling the degree of said displacement regulation in accordance with the degree of the acceleration eiect on said system at said angle.

5. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support, mechanism for regulating the displacement of the liquid in said system in response to said acceleration, operative connections between said means and said mechanism for compensating for the eiect of acceleration on said system, second mechanism for regulating the ow of the liquid through the communication between said receptacles during said acceleration displacement thereof, and operative connections between said means and said second mechanism for modifying the response of said liquid to said acceleration.

6. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support, mechanism for regulating the displacement of the liquid in said system in response to said acceleration, operative connections between said means and said mechanism for compensating for the eilect of acceleration on said system, means responsive to the angle of rotation of said system interposed in the connections between said first means and said mechanism for controlling the degree of said displacement regulation in accordance with the degree of the acceleration effect on said system at said angle, second mechanism for regulating the flow of the liquid through the communication between said receptacles during said acceleration displacement thereof, and operative connections between said means and said second mechanism for modifying the response of said liquid to said acceleration.

7. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicatingv receptacles mounted? at opposite sides of the gyroscope and containing a liquidi displaceable inA responseto acceleration ofV the' gyroscopev support, and means'for rotating said gyroscope support and system about. a substantially vertical axis, thecombi'nati'onoi means responsive to acceleration of the gyroscope support, counterdisplacement mechanisml including a member immersible in the liquid' inY each receptacle for regulating the displacement of liquid therein, operative connections between said means and said mechanism for eiecting thev immersion of said. members in the corresponding receptacles, means responsive to the angle of rotation of said system interposed'in the connections between said first means and said mechanism for controlling the degree of said displacement regulation in accordance with the degree of' the acceleration eiiect on said system at said angle, second mechanism. for regulating the flow of the liquid through the communication between said receptacles during said acceleration displacement thereof, and operative connections between said means and said second mechanism for modifying the response of said liquid to said acceleration.

8. In a stable element having a universally supported verticalY axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system continuously about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support in one direction, mechanism for regulating the displacement of' the liquid in said system in response to said acceleration while permitting substantially free flow of the liquid between said communicating receptacles, operative connections between said means and said mechanism for compensating i-or the eiect of acceleration.

on said system, and means responsive to the angle of rotation of said system interposed in said connect1ons for controlling said mechanism in accordance with the effect of said acceleration inV said direction on said system at said angle,

9. In a stableV element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid -displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support in one direction, counter-displacement mechanism including a member immersible in the liquid in each receptacle for increasing the head of liquid therein, operative connections between said means and said mechanism for eiecting the immersion of said members in the corresponding receptacles, and means responsive to the angle of rotation of said system interposed in said connections for controlling said mechanism in accordance with port and system continuously about-a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support in a plurality of dii-ferent directions, mechanism for regulating the displacement of the liquid in said system in response to said acceleration while permitting substantially free iiow of the liquid between said communicating receptacles, operative connections between said means and said mechanism for compensating for the effect of acceleration on said system, and means responsive to the angle of rotation of saidV system interposed in said connections for selectively controlling said mechanism in accordance with the effect of said acceleration aiecting said system in the direction of orientation of the latter.

l1. In a stable element having a universally supported vertical axis gyroscope, an erectingy system thereon including a pair of communicatine receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support `and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support for developing a voltage proportional thereto, electro-mechanical mechanism for regulating the displacement of the liquid in said system in response to said acceleration, and operative connections between said acceleration responsive means and said mechanism for compensating for the effect of acceleration on said system.

l2. In a stable element having a universally. supported vertical axis gyroscope, an erecting system thereon including; aY pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration ofA the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to. acceleration of the gyroscope support for developing a voltage proportional thereto, electro-mechanical mechanism for regulating the displacement of the liquid in said system in response to said acceleration, operative connections between said' acceleration responsive means and said mechanism for compensating for the effect of acceleration on said system, and means responsive to the angle of rotation of said system interposed in said connections for regulating the voltage impressed on said mechanism in accordance with the degree of acceleration effect on said system at said angle.

i3. In a stable element having a universally l supported vertical axis gyroscope, an erecting the effect of said acceleration in said. direction on said system at said angle.

10. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon includingv a pair of communicating receptacles mountedV at opposite sides of the gyroscope and containing a. liquid displaceable in response to acceleration of the gyroscope support, and means for rotating, said gyroscope'supsystem thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical" axis, the combination of means responsive to acceleration of the gyroscope support for developing a voltage proportional thereto, electro-mechanical mechanism for regulating the displacement of the liquid in said system in response to said acceleration, operative connections between said acceleration responsive means and said mechanism for compensatingfor the effect of acceleration on said system, and a voltage divider interposed in said connections for regulating the voltage impressed on said mechanism in accordance with the degree of acceleration eiect on 11` said system in the direction of orientation of the latter, the voltage output of said voltage divider being dependent upon the angular position of the rotatable gyroscopic support.

14. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support in one direction, second means responsive to acceleration of the gyroscope support in another direction, electromechanical mechanism for regulating the displacement of the liquid in said system in response to said acceleration, operative connections between said rst and second acceleration responsive means and said mechanism for compensating for the effect of acceleration on said system, and a voltage divider providing an output in accordance with the rotation of said gyroscope support interposed in said connections for selectively regulating the voltage impressed on said mechanism in accordance with the degree of acceleration effects in said directions on said system at any angle of orientation thereof.

15. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration oi the gyroscope support in a plurality of different directions, counter-displacement mechanism including a member immersible in the liquid in each receptacle for regulating the displacement of liquid therein, operative connections between said acceleration responsive means and said mechanism for eiecting the immersion of said members in the corresponding receptacles,

and means responsive to the angle of rotation of said system interposed in said connections for selectively controlling said mechanism in accordance with the eii'ect of said acceleration affecting said system in the direction of orientation of the latter.

16. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support for de- Veloping a voltage proportional thereto, electromechanical counter-displacement mechanism including a member immersible in the liquid in each receptacle for regulating the displacement of liquid therein, operative connections between said acceleration responsive means and said mechanism for effecting the immersion of said members in the corresponding receptacles, and means responsive to the angle of rotation of said system interposed in said connections for regulating the voltage impressed on said mechanism in accordance with the degree of acceleration eiect on said system at said angle.

1'7. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support for developing a voltage proportional thereto, electromechanical counter-displacement mechanism including a member immersible in the liquid in each receptacle for regulating the displacement of liquid therein, operating connections between said acceleration responsive means and said mechanism for effecting the immersion of said members in the corresponding receptacles, and a voltage divider providing an output in accordance with the rotation of said gyroscope support interposed in said connections for regulating the voltage impressed on said mechanism in accordance with the degree of acceleration effect on said system in the direction of orientation of the latter.

18. In a stable element having a universally supported vertical axis gyroscope, an erecting .system thereon including a pair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support in one direction, second means responsive to acecleration of the gyroscope support in another direction, electro-mechanical counter-displacement mechanism including a member immersible in the liquid in each receptacle for regulating the displacement of liquid therein, operative connections between said rst and second acceleration responsive means and said mechanism for eiecting the immersion of said members in the corresponding receptacles, and a voltage divider providing an output in accordance with the rotagyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support for developing a voltage proportional thereto, counterdisplacement mechanism for each receptacle for regulating the displacement of liquid introduced therein in response to said acceleration, electrical motive means connected to each mechanism for operating the same, electrical connections between said acceleration responsive means and each motive means, and a voltage divider providing an output in accordance with the rotation of said gyroscope support interposed in said connections for regulating the voltage impressed on each motive means in accordance with the degree of acceleration effect on said system in the direction of orientation of the latter to 13 thereby proportionally regulate the degree of counter-displacement of the liquid.

20. In a stable element having a universally supported vertical axis gyroscope, an erecting system thereon including a Ipair of communicating receptacles mounted at opposite sides of the gyroscope and containing a liquid displaceable in response to acceleration of the gyroscope support, and means for rotating said. gyroscope support and system about a substantially vertical axis, the combination of means responsive to acceleration of the gyroscope support for developing a Voltage proportional thereto in one predetermined direction, second means responsive to acceleration of said support in another predetermined direction for developing a voltage proportional thereto, counter-displacement mechanism for each receptacle for regulating the displacement of liquid introduced therein in response to said acceleration, electrical motive means connected to each mechanism for operating the same, a voltage divider providing an output in accordance with the rotation of said gyroscope support and havingA taps arranged in said relative directions and connected to the corresponding rst and second means, and opposite 14 brushes on said divider connected to corresponding motive means for regulating the voltage impressed on each motive means in accordance with the degree of acceleration effect on said system in the direction ofV orientation of the latter to thereby proportionally regulate the degree of counter-displacement of the liquid.

ARTHUR P. DAVIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,644,921 Henderson Oct. 11, 1927 1,866,706 Henderson July 12, 1932 1,887,318 Mahoney Nov. 8, 1932 1,923,290 Wood Aug. 22, 1933 2,087,961 Anscott July 27, 1939 FOREIGN PATENTS y Number Country Date 13,280 Great Britain 1915 125,-660 Great Britain May 1, 1919 

